The present inventive concept disclosed herein relates to an apparatus and a method for manufacturing carbon nanotubes, and more particularly, to a fluidized bed-type apparatus for manufacturing carbon nanotubes and a method of manufacturing carbon nanotubes with the apparatus.
Carbon atoms of carbon nanotubes are connected to their three nearest-neighbor carbon atoms through SP2 bonds to form hexagonal rings. Such a hexagonal ring is repeated in a honeycomb shape to form a graphite sheet, and the graphite sheet is rolled to form a cylindrical shape. Such a cylindrical structure generally has a diameter ranging from several nm to several hundreds of nm, and has a length several ten times through several thousand times or more times greater than the diameter.
Such carbon nanotubes may be classified into a single-wall nanotube, a multi-wall nanotube, and a rope nanotube according to a rolled shape of a graphite sheet. Also, the carbon nanotubes may have various electric characteristics according to a rolled angle and a structure of a graphite sheet. For example, an armchair-type carbon nanotube conducts electricity like a metal, and a zigzag-type carbon nanotube has semiconducting characteristics.
Since the carbon nanotubes have excellent electric characteristics, a high mechanical strength, and stable chemical characteristics, they can be widely applied to various technical fields and draw attention as a future new material. For example, the carbon nanotubes can be applied to secondary cells, electrodes of electrochemical storage devices such as fuel cells or super capacitors, electromagnetic wave shields, field emission displays, or gas sensors.
Typical methods of synthesizing carbon nanotubes include an electric arc method, a laser vaporization method, a pyrolysis vapor deposition method, and a plasma chemical vapor deposition, in which the pyrolysis vapor deposition method are mainly used. The pyrolysis vapor deposition method includes growing carbon nanotubes through a metal catalyst while discharging a gas containing carbon into a high temperature reactor, and the carbon nanotubes may be synthesized in the state where a fluidized bed of the metal catalyst is formed by supplying a fluidizing gas into the reactor.